50ZHK: Installation Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
9
A10026
Fig. 13 – Control Connections
3. Make the following inspections:
a. Inspect for shipping and handling damages, such as broken lines,
loose parts, disconnected wires, etc.
b. Inspect all field- and factory-wiring connections. Be sure that
connections are completed and tight.
c. Ensure wires do not touch refrigerant tubing or sharp sheet metal
edges.
d. Inspect coil fins. If damaged during shipping and handling,
carefully straighten fins with a fin comb.
4. Verify the following conditions:
a. Make sure that outdoor-fan blade is correctly positioned in fan
orifice. See Outdoor Fan Adjustment section.
b. Make sure that air filter is in place.
c. Make sure that condensate drain pan and trap are filled with
water to ensure proper drainage.
d. Make sure that all tools and miscellaneous loose parts have been
removed.
Start-up
Step 1 – Check for Refrigerant Leaks
Proceed as follows to locate and repair a refrigerant leak and to charge
the unit:
1. Locate leak and make sure that refrigerant system pressure has been
relieved and reclaimed from both high- and low-pressure ports.
2. Repair leak following accepted practices.
NOTE:
Install a filter drier whenever the system has been opened for
repair.
3. Add a small charge of Puron (R-410A) refrigerant vapor to system
and leak-test unit.
4. Recover refrigerant from system and evacuate to 500 microns if no
additional leaks are found.
5. Charge unit with Puron (R-410A) refrigerant, using an accurate
scale. Refer to unit rating plate for required charge.
Step 2 – Start-Up Cooling and Make Adjustments
Complete the required procedures given in the Pre-Start-Up section
before starting the unit. Do not jumper any safety devices when
operating the unit. Do not operate the unit in cooling mode when the
outdoor temperature is below 40°F (4.4°C) (unless accessory
low-ambient kit is installed). Do not rapid cycle the compressor. Allow 5
min. between “on” cycles to prevent compressor damage.
Checking Cooling and Heating Control Operation
Start and check the unit for proper cooling control operation as follows:
1. Place room thermostat SYSTEM switch in OFF position. Observe
that blower motor starts when FAN switch is placed in ON position
and shuts down within 60 sec. when FAN switch is placed in AUTO
position.
2. Place SYSTEM switch in COOL position and FAN switch in
AUTO position. Set control below room temperature. Observe that
compressor, outdoor fan, and indoor blower motors start and that
reversing valve shifts. Observe that cooling cycle shuts down when
control setting is satisfied. Reversing valve (RV) remains energized.
3. Place system switch in HEAT position. Observe that compressor,
indoor fan and outdoor fan energize (Reversing Valve is
deenergized in heat pump heating mode). Set control above room
temperature. Observe that heating cycle shuts down when control
setting is satisfied.
4. When using an automatic changeover room thermostat, place both
SYSTEM and FAN switches in AUTO positions. Observe that unit
operates in Cooling mode when temperature control is set to call for
Cooling (below room temperature), and unit operates in Heating
mode when temperature control is set to call for Heating (above
room temperature).
Step 3 – Refrigerant Charge
Refrigerant Charge — The refrigerant system is fully charged with
Puron (R-410A) refrigerant and is tested and factory sealed. Amount of
refrigerant charge is listed on unit nameplate and in
. Unit must
operate a minimum of 15 minutes before checking charge.
NOTE:
Adjustment of the refrigerant charge is not required unless the
unit is suspected of not having the proper Puron (R-410A) charge.
NOTE:
Unit sizes 024-042 have fixed orifice refrigerant metering
devices. There is a different charging procedure for both expansion
devices. Refer to the correct procedure for your unit.
No Charge
Use standard evacuating techniques. After evacuating system, weigh in
the specified amount of refrigerant (refer to
).
Low Charge Cooling
024-042 Units, Fixed Indoor Metering Device:
1. Operate unit a minimum of 10 minutes before checking charge.
2. Measure suction pressure by attaching an accurate gauge to
compressor suction side service port.
3. Measure suction side temperature by attaching an accurate
thermisitor type or electronic thermometer to suction line about 10
in. from compressor.
4. Measure outdoor air dry-bulb temperature with thermometer.
WARNING
!
PERSONAL INJURY AND ENVIRONMENTAL HAZARD
Failure to relieve system pressure could result in personal injury and/or
death.
Relieve pressure and recover all refrigerant before system repair or
final unit disposal.
Wear safety glasses and gloves when handling refrigerant. Keep torches
and other ignition sources away from refrigerants and oils.
Thermostat
Unit Control
G
Y
W2
R
RED
GREEN
YELLOW
O
ORANGE
C
BROWN
WHITE
and subbase
Power
